This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. A centerpiece instrument at ACERT is our millimeter-wave c.w./pulse spectrometer operating at 95GHz. In pulse mode, this instrument is capable of producing precisely-defined 1.2KW r.f. pulses down to 2ns widths and 1 ns absolute resolution. In its current configuration, the spectrometer utilizes a PulseBlaster ESR-300 (SpinCore Technologies, Inc.) with a proprietary high resolution broadside-parallel to time-serial converter card (ACERT-PBHR) to create an interim timing system producing r.f. control pulses with 1ns resolution. However, there are several undesirable operational tradeoffs which have been necessarily accepted in originally adapting the existing commercial timing card to our HFHF use. These drawbacks include the relatively coarse (3.2 ns) relative timing between control channels and the undesirably long delay time (16 ns) needed between programmable transitions on any one timing line. These limitations add unnecessary complexity to the pattern generation software and, to a minor extent, constrain the timing patterns actually available for the experiment. There is also an approx. 300 ps peak-to-peak timing uncertainty in the high resolution channel, which becomes consequential once other deadtime contributing factors in the spectrometer have been corrected. We are in the process of addressing these issues with a spectrometer control system upgrade incorporating a high resolution timing card (Chase Scientific DWG-1000) that outputs 12 channels with intrinsic 1ns resolution. Because the spectrometer operating system is Linux based, and suitable drivers are not yet available, some additional work will be required to incorporate the timing upgrade hardware. Presently, we are completing EIK h.v. modulator modifications which will result in a significant reduction of deadtime with the existing timing system still in place. Soon after completion and qualification of the modulator upgrades with the present timing hardware, we expect to install the new Chase Scientific timing card and modify the spectrometer control software as necessary to fully utilize its capability for additional deadtime reduction.